I missed two consecutive periods recently and idk why

first of all I am a virgin, so in no way could I be pregnant. my periods have been always very regular and to the point where I could predict the day and time I would get it. in April, I had my period as normal but then it was May, it never showed up. June came and went, it never showed up. during like the end of May and beginning of June, for about three weeks, I spotted with varying flows (sometimes it was extremely light and light brown and sometimes it was SO dark and gloopy). finally, in July it started up again (right before I went on vacation :( but at least it came back). this experience was super weird for